Electron-capture mass spectrometry: recent advances.
Electron-capture mass spectrometry: recent advances.
复制标题
电子捕获质谱：最新进展。
DOI：
10.1016/s0021-9673(00)00364-2
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Giese,RW
中科院分区：
文献类型：
--
作者：
Giese,RW
电子俘获(EC)是一种灵敏、选择性的电离技术。在最常见的EC形式中，敏感分析物(电泳液)在从气相色谱(GC)柱洗脱后被检测到，标准的低阿托摩尔检测下限是常规的。高效液相色谱可以在GC-EC-MS检测之前方便样品的清理，但“看不见的”分析物的保留时间和保留时间的转移可能是困难的。固相萃取避免了这些困难，但净化和回收的程度可能会成为问题。替代的电泳衍生化试剂可用来帮助处理干扰，新的试剂如“AMACE1”正在出现。可释放形式的电泳剂可用作标记大分子的标签，其动机是多重配基类型分析的愿望。传统的用于EC的气相离子源，特别是壁面反应的作用还不是很清楚。使用电子单色仪调整电子能量，增加了EC-MS提供的选择性和信息。高分辨率和串联的EC-MS测量正在出现。电子捕获解离是一种对中小分子多肽进行测序的新技术，相对于其他MS技术，它具有提供更广泛的序列信息的优点。粒子束EC-MS往往不如GC-EC-MS灵敏，但也并非总是如此。最近的研究表明，EC-MS可以在普通激光解吸飞行时间质谱仪上完成，也可以通过大气压化学电离来完成。这里详细讨论了两种应用：胆汁酸和氧化苯丙氨酸。EC-MS是一种在特殊情况下用于痕量分析的有用技术，其用途范围正在扩大(定性分析和检测更多的极性和更大的分子)，这是基于这项技术在化学和仪器方面的进展。
Electron-capture (EC) is a sensitive and selective ionization technique for mass spectrometry (MS). In the most familiar form of EC, a susceptible analyte (electrophore) is detected after eluting from a gas chromatography (GC) column, where a low attomole detection limit for standards is routine. High-performance liquid chromatography can facilitate sample cleanup prior to detection by GC–EC-MS, but carryover and shifts in retention time for the “invisible” analyte can be difficulties. Solid-phase extraction avoids these difficulties, but the degree of cleanup and recovery can be problems. Alternative electrophoric derivatizing reagents are available to help deal with interferences, and new reagents such as “AMACE1” are emerging. Releasable forms of electrophores can be used as tags for labeling macromolecules, motivated by the desire to multiplex ligand-type assays. The conventional, gas-phase ion source for EC is not well-understood, especially the role of wall reactions. Using an electron monochromator to tune the electron energy adds to the selectivity and information provided by EC-MS. High-resolution and tandem EC-MS measurements are emerging. Electron-capture dissociation is a new technique to sequence small- to medium-sized peptides, having the advantage of providing more extensive sequence information relative to other MS techniques. Particle-beam EC-MS tends to be less sensitive than GC–EC-MS, but not always. Recently it was demonstrated that EC-MS can be accomplished on an ordinary laser desorption time-of-flight mass spectrometer, and also by using atmospheric pressure chemical ionization. Two applications are discussed here in detail: bile acids and oxidized phenylalanine. EC-MS is well-established as a useful technique for trace analysis in special cases, and the scope of its usefulness is broadening (qualitative analysis and detection of more polar and larger molecules), based on advances in both the chemical and instrumental aspects of this technique.